The George M. O?Brien Urology Research Center at the University of Pennsylvania entitled ?Bladder Wall Remodeling in LUTS? has three key elements: (1) the laboratories of five principal investigators and the Co-PIs that bring expertise in molecular biology, cellular biology, neuroscience, biochemistry, physiology, pharmacology, and pathology; (2) an Administrative Core (Core A) to provide administrative and fiscal oversight, quality control for the research within individual projects and coordination of the research and interactions in the Center; (3) a Bladder Tissue Core (Core B) to serve as a resource for smooth muscle tissue of the LUTS from rabbits, rats, and mice (normal and obstructed bladders and urethra). In addition, we have Educational and Enrichment and Pilot and Feasibility (P&F) programs to attract young investigators and established investigators in working in other biomedical areas to urologic research. The four projects are: (1) Social-stress-induced urinary dysfunction: A model of dysfunctional voiding from Rita J. Valentino; (2) Bladder wall remodeling following alteration of urothelial structure from Pamela S. Howard (in collaboration with Dr. Tung-Tien Sun of NYU); (3) Mechanism for obstruction-induced detrusor remodeling: role of hypoxia and stretch from Samuel K. Chacko; and (4) Extracellular matrix changes response to obstruction from Edward J. Macarak. The two P&F projects are: (1) Urethral function in females: A Role for estrogen from Shaohua Chang; and (2) The effect of PBOO and estrogen on detrusor smooth muscle in female rabbits from Gina M. Northington. The focus of the O?Brien Program is to elucidate the mechanism for social stress- and PBOO-induced functional and structural changes in the bladder wall leading to LUTS. These studies will provide a useful model for dysfunctional voiding in children and elucidate the molecular basis for urinary dysfunction in menopausal women and aging men with BPH-induced PBOO. A better understanding of the basic mechanisms for alteration of the structure and function of the bladder wall and urethra in LUTS would help to develop therapeutic strategies targeting altered molecular events that cause altered function in lower urinary tract. [unreadable]